Without wishing to bog this whole thing down with semantics, I have to say, I'm never really that sure where people are coming from when they talk about transsexualism being a 'state of mind.' I'm not concerning myself with other aspects of gender variance, because then the debate just becomes like trying to knit fog.
I think it was Chibiusa, who said earlier in the debate about knowing from a very early age that things weren't right. I can absolutely identify with this....
....And with that in mind, I feel I could no more call my transsexuality a 'state of mind' that I could watch a moth fly round a lightbulb and then put it down to the moths 'state of mind.' I was driven to the operating table by an all consuming need, that was primal in nature. That's not something that I could ever describe as a state of mind.
If you're transsexual, you just know it, and that's really all there is to it. Unfortunately, I grew up before the the internet, and transsexuality was something that was hardly discussed or known about. So although I knew I was trans, I didn't have a label to pin on myself or have the faintest idea what to do about it. Had things been different, then I certainly would have transitioned at an earlier age. But that's ancient history now.
If you know you're transsexual, my advice would always be to find a suitably experienced councillor, and if you're still relatively young, get on hormone blockers ASAP!!! That way, if you decide to go ahead you'll effect a much better transition. And if not, no worries, the hormone blockers won't do any lasting damage.